I am able to reproduce the issue on debian 7 with Percona Server 5.1/5.5/5.6. Installed PS packages from percona repo and during upgrade i found links are re-created.
* Verified from rc.d scripts and found mysql is added once i installed PS 5.5 from Percona repository.
# ls -la /etc/rc* | grep mysql
lrwxrwxrwx 1 root root 15 Dec 24 06:18 K02mysql -> ../init.d/mysql
lrwxrwxrwx 1 root root 15 Dec 24 06:18 K02mysql -> ../init.d/mysql
lrwxrwxrwx 1 root root 15 Dec 24 06:18 S17mysql -> ../init.d/mysql
lrwxrwxrwx 1 root root 15 Dec 24 06:18 S17mysql -> ../init.d/mysql
lrwxrwxrwx 1 root root 15 Dec 24 06:18 S17mysql -> ../init.d/mysql
lrwxrwxrwx 1 root root 15 Dec 24 06:18 S17mysql -> ../init.d/mysql
lrwxrwxrwx 1 root root 15 Dec 24 06:18 K02mysql -> ../init.d/mysql
* Removed mysql service from rc.d directory to prevent auto-start of mysql service on OS reboot.
# update-rc.d -f mysql remove
update-rc.d: using dependency based boot sequencing
# ls -la /etc/rc* | grep mysql
Upgraded to Percona Server 5.6 and found links are re-created.
I am able to reproduce the issue on debian 7 with Percona Server 5.1/5.5/5.6. Installed PS packages from percona repo and during upgrade i found links are re-created.
# apt-get install percona- server- server- 5.5 percona- server- client- 5.5 percona- server- common- 5.5
* Verified from rc.d scripts and found mysql is added once i installed PS 5.5 from Percona repository.
# ls -la /etc/rc* | grep mysql
lrwxrwxrwx 1 root root 15 Dec 24 06:18 K02mysql -> ../init.d/mysql
lrwxrwxrwx 1 root root 15 Dec 24 06:18 K02mysql -> ../init.d/mysql
lrwxrwxrwx 1 root root 15 Dec 24 06:18 S17mysql -> ../init.d/mysql
lrwxrwxrwx 1 root root 15 Dec 24 06:18 S17mysql -> ../init.d/mysql
lrwxrwxrwx 1 root root 15 Dec 24 06:18 S17mysql -> ../init.d/mysql
lrwxrwxrwx 1 root root 15 Dec 24 06:18 S17mysql -> ../init.d/mysql
lrwxrwxrwx 1 root root 15 Dec 24 06:18 K02mysql -> ../init.d/mysql
* Removed mysql service from rc.d directory to prevent auto-start of mysql service on OS reboot.
# update-rc.d -f mysql remove
update-rc.d: using dependency based boot sequencing
# ls -la /etc/rc* | grep mysql
Upgraded to Percona Server 5.6 and found links are re-created.
* Removed PS 5.5 packages. server- server- 5.5 percona- server- client- 5.5 percona- server- common- 5.5
# apt-get --purge remove percona-
* Started upgrade to PS 5.6 server- server- 5.6 percona- server- common- 5.6 percona- server- client- 5.6
# apt-get install percona-
# ls -la /etc/rc* | grep mysql
lrwxrwxrwx 1 root root 15 Dec 24 06:35 K02mysql -> ../init.d/mysql
lrwxrwxrwx 1 root root 15 Dec 24 06:35 K02mysql -> ../init.d/mysql
lrwxrwxrwx 1 root root 15 Dec 24 06:35 S17mysql -> ../init.d/mysql
lrwxrwxrwx 1 root root 15 Dec 24 06:35 S17mysql -> ../init.d/mysql
lrwxrwxrwx 1 root root 15 Dec 24 06:35 S17mysql -> ../init.d/mysql
lrwxrwxrwx 1 root root 15 Dec 24 06:35 S17mysql -> ../init.d/mysql
lrwxrwxrwx 1 root root 15 Dec 24 06:35 K02mysql -> ../init.d/mysql
So, mysql daemon script added after upgrade implicitly to rc.d directory.